Toward the bottom there's one for Pentax K mount. I've never done pinhole photography, but it looks fun. Does anybody know how these caps work? It sure would be nice to use to start using the Super again.

about a year ago I took a spare body cap and drilled a hole in it, then used foil/electrical tape and experimented with different sized holes and ended up with some neat pic's. It was a lot cheaper than 45 bucks. I did this with a Pentax digital SLR which was nice because I got immediate feedback on the effect I got with different sized holes and shutter speeds. I misplaced that particular body cap earlier this year, but it can be made form any body cap as long as it's designed for your particular lens mount, It's cheap fun.

Edit: Since this is an analog forum, I used the digital with my homemade body cap to get approximate hole size/shutter speeds at different iso values so I could use them as a starting point on my Pentax film pinhole photography (wink, wink).

Hmm. Home built... I don't really like a lot of home built pictures I've seen - the main problem probably being imprecision in the hole causing excessive softness. I thought this product might get around that. But then again, Denver Camera Exchange has a whole bin full of spare caps. It shouldn't be too hard to find somebody to laser drill a hole in a piece of soda can. Average, you might be on to something. Either that or your on something.

My original question was meant more along the lines of "I'm thinking that to use this I would replace the existing cap, put it on bulb setting with a cable release and use the mirror as the shutter." Does that sound right?

its really not hard to make a nice sharp pinhole if you have one of these start the hole with a pin over something sort of soft - like phone book so that you can get an actual depression or even small hole - and then start to rub it on the plate (wet to lubricate it)you can start to widen the hole up with the needle, a little more pressure and the plate. when you are done, burnish the edges of the hole by just twisting the metal on the end of the needle.

I have one those caps for my Minolta and its decent - the price a little hi but not that bad and it gets you going immediately - though I found I can get sharper stuff with my own if I take the time with it.

scan it at the highest possible resolution you can (mine is like 2000 dpi) enlarge that image in a graphics program - Gimp is free - and then select it with a circle tool to tell you how many pixels wide it is. Multiply: number of pixels * inches-per-pixel and voila - pinhole diameter!

I remeasured mine with a microscope once and the method was pretty damned accurate.